Conventionally, in order to support a driver of a vehicle, a gaze direction of the driver is detected to determine whether the driver is in an attentive state. When the gaze direction of the driver is out of a normal range, the driver is determined to be in an inattentive state, and a warning is given to the driver.
Further, a field of a vision varies from individual to individual. Thus, the normal range used to determine whether the driver is in the inattentive state needs to be changed from individual to individual. JP 2009-176112 A discloses an apparatus in which the normal range is settable by an operation of the driver. Specifically, the driver operates switches disposed in a compartment of the vehicle to input information relative to the normal range.
In JP 2009-176112 A, the driver needs to input numbers indicating the normal range to the apparatus via the switches. For example, the driver inputs minus thirty degrees to plus thirty degrees (−30 degrees to +30 degrees) to the apparatus. Thus, the apparatus disclosed in JP 2009-176112 A necessarily includes the switches for setting the normal range. Since, hardware configurations, such as the switches, need to be added, it is difficult to add the function of setting the normal range to the apparatus.